Barely an episode of this fantasy series goes by without a moment that causes slack-jawed shock from its viewers. George RR Martin, who wrote the original Songs of Ice and Fire novel series on which the drama is based, has a brutal, ruthless approach to storytelling. But which of the Game of Thrones plot twists have been the most shocking so far?

CONTAINS SPOILERS OF SEASONS 1-4

20. Jon Snow kills Qhorin Halfhand

In order to gain the trust of the band of wildlings that hold them captive, senior member of the Night’s Watch Qhorin Halfhand (Simon Armstrong) instructed Jon Snow (Kit Harington) to kill him – so he did. After a tense sword battle, Jon thrusted his weapon through his mentor’s torso.

At the end of season two we finally get a proper glimpse of the spooky White Walkers that have made the wildlings so nervous. Trapped behind a rock – yet somehow left unharmed – Sam Tarly (John Bradley) struggled to hold back the tears as an army of winter zombies walked through the snow.

18. Ygritte's death

A pair of star-cross'd lovers, Jon Snow (Kit Harington) and Ygritte (Rose Leslie) were from opposite sides of the tracks – she a wildling, he a member of the Night's Watch. Yet still they found love, until his secret agent status was exposed and she put three arrows in him as he ran away. But Jon survived and the two would meet again amidst the Battle for Castle Black. It was almost poetic: their eyes met, their faces softened... and then she was shot through the heart by the young boy whose family had been murdered by the wildlings a few episodes ago.

17. Jaime Lannister escapes from jail

He’s a wily one, that Jaime Lannister (Nikolaj Coster-Waldau). Befriending his innocent, star-struck cousin (Karl Davies) in prison, he then savagely murdered him in order to distract the guard and make his escape. Poor lad, he was just so happy to be in the presence of the great Kingslayer.

16. Wildfire

Tyrion Lannister (Peter Dinklage) proved his worth, even if his family still wouldn’t recognise it, when he arranged for the use of Wildfire during the Battle of Blackwater Bay. As Stannis Baratheon (Stephen Dillane) led his army to King’s Landing, with the hope of taking the Iron Throne, the Lannister army unleashed a dazzling green explosion in the middle of the Bay, ensuring their victory.

15. Daenerys gets her dragons

The first time we to see what Daenerys Targaryen (Emilia Clarke) is made of. Her husband is dead, her Khalasar on the brink of desertion. So she proves her toughness by strapping the witch who bewitched Khal Drogo (Jason Momoa) to his funeral pyre before walking in herself and emerging with three fire-breathing dragon-children.

The Red Priestess Melisandre (Carice van Houten)was a devious schemer from the very beginning but when her pregnancy came to completion we learned that her magical powers are not only real but decidedly creepy. She gave birth to the “shadow”, a mysterious spirit that swept straight off to assassinate Lord Renly (Gethin Anthony).

13. Daenerys frees the slaves

Ser Jorah Mormont (Iain Glen) was always convinced of Daenerys Targaryen’s (Emilia Clarke) regal potential, Ser Barristan Selmy (Ian McElhinney) less so. No doubt was left after this seriously rousing display of tactical greatness when, in one fell swoop, she freed the Unsullied army from their captors, earned their loyalty and set her dragon on evil slaver Kraznys mo Nakloz (Dan Hildebrand).

12. Jaime Lannister’s hand is cut off

We finally got to see a bit of kindness in the eldest Lannister sibling, as he tactically talked Locke (Noah Taylor) out of allowing his men to rape Brienne of Tarth (Gwendoline Christie). But moments later his arrogance got the better of him and Locke grew tired of Jaime’s persistent attempts to bribe him. Suddenly the Kingslayer and master swordsman was no longer in possession of his sword hand. To add insult to injury, the next day Locke forced him to wear the severed hand on a string around his neck.

11. Theon takes Winterfell

Theon Greyjoy (Alfie Allen) cemented his betrayal of the Starks when, desperate to impress his father but too stupid to realise that ignoring orders is not the way to do it, he attempted to take Winterfell. It didn’t work in the end but it did see him commit the murder and incineration of two young boys (whom he tries to pass off as Rickon and Bran Stark) and, even more shockingly, the graphic beheading of Ser Rodrik Cassel (Ron Donachie).

10. Tyrion's revenge

By the end of season four Tyrion Lannister (Peter Dinklage) had finally had his fill of being treated like the family embarrassment. Broken out of his prison cell by his faithful brother Jamie (Nikolaj Coster-Waldau), mere hours before he was due to be wrongfully executed for the murder of King Joffrey, Tyrion took a quick detour through the castle on his way to freedom. In his father's room he found his former lover, Shae (Sibel Kekilli) asleep in Tywin's (Charles Dance) bed. This was one betrayal too far. When she lunged for a knife he throttled her then shot his father with a crossbow while he sat on the privy, denying Tywin the dignity that he had held back from Tyrion for so long.

9. Bran Stark is pushed through a window

The second-youngest Stark boy (Isaac Hempstead-Wright) caught Jaime and Cersei Lannister ((Nikolaj Coster-Waldau and Lena Headey) in an incestuous tryst when he climbed the castle walls to the tower window. Ruthless Jaime quickly solved the problem by casually shoving Bran to his apparent death.

A brother and sister having sex is shocking. A brother raping his sister is even more shocking. A brother raping his sister in front of their murdered child’s dead body? That’s a special GoT level of shocking. For here is a world where incest has become almost romantic and rape is something you get over in a matter of weeks. So when Jaime Lannister (Nikolaj Coster-Waldau) took his revenge on his twin/lover Cersei (Lena Headey) for rejecting and ridiculing him... well, it's now just water under the bridge.

7. Daenerys eats a horse heart

This one is a particularly stomach-churning scene. In order to give birth to a strong son, Daenerys Targaryen (Emilia Clarke) must eat a whole raw stallion heart without vomiting. Being able to watch it without retching can also be considered an achievement.

6. The severing of Theon Greyjoy’s penis

Despite the copious amounts of rape in Game of Thrones, the gruesome nature of this scene must make it the one that most causes viewers to firmly squeeze their legs shut. Kidnapped by Ramsay Snow (Iwan Rheon), Theon Greyjoy was tortured at length. By this point in the third series, Theon had transformed into an entirely unlikeable, hot-headed little rotter, so he lost a few sympathy points. But when Ramsay savagely chopped off his penis and then taunted him by emphatically eating a sausage, well, we learned that men’s genitals aren’t safe in Westeros either.

5. The golden crown

Never had there been a murder more pleasing than that of Daenerys Targaryen's (Emilia Clarke) vile, spoiled big brother, Viserys (Harry Lloyd) – even if it was via a method so sadistic and violent that few of us would have ever thought of it before. Finally bored of Viserys’s demands for gold crown, Khal Drogo (Jason Momoa) gave him what he wanted. With molten gold poured over his head, Viserys died a screaming death.

4. The Purple Wedding

The Red Wedding was brutal (see number 2), so surely the next wedding in the series wouldn’t just go the same way? That would be too easy, too repetitive. Turns out, none of that mattered. Even the comparatively undramatic method of killing someone by poison (as opposed to, say, stabbing them in their pregnant belly), somehow left us frozen with shock. King Joffrey (Jack Gleeson) was the one we wanted to see dead the most, but it coming after his repeated taunts of his uncle Tyrion (Peter Dinklage) made his brutally violent asphyxiation seem all the more satisfying. It’s just a shame that it left Tyrion looking like he’d been caught red-handed.

3. The execution of Ned Stark

We really should have seen it coming (well, those who had read the books already did); any character played by Sean Bean is destined to die. But lovely, (almost) entirely honourable Ned Stark seemed an integral part of the plot. Surely they wouldn’t allow his head to be chopped off by a former Dr Feelgood guitarist? Well, they did exactly that as Ilyn Payne (Wilko Johnson) performed the deed and thus taught us early on that no one is safe.

2. The Red Wedding

It seemed fishy from the beginning. No one in Westeros takes anything lightly. Walder Frey (David Bradley) appeared surprisingly relaxed about Robb Stark (Richard Madden) marrying Talisa (Oona Chaplin) instead of the Frey daughter to whom he was betrothed. But by now we knew just how willing George RR Martin is to maim or kill our favourite characters. The whole episode is a rattling pressure pot and just when we adoring viewers thought we’d made it through with no serious fatalities, the last five minutes happened. Talisa, Robb and Catelyn Stark – plus poor Grey Wind – dead. Oh George.

1. A skull-crushing death

It was a moment that’s now seared into the memory of all who watched it and is now possibly the most shocking death ever seen on prime time television. The widely loved character of Prince Oberyn Martell (Pedro Pascal), aka The Red Viper, stepped up to be Tyrion Lannister’s (Peter Dinklage) champion in the dwarf’s trial by combat as a way of exacting his long-held desire for revenge against the rapist and murderer of his sister – The Mountain (Hafþór Júlíus Björnsson). But Oberyn’s arrogance and his lust for retribution got the better of him and when we thought The Mountain had had it, he surged back into life, grabbing Oberyn by the head, plunging his thumbs into his eyes and crushing his skull with his bare hands. Remember those innocent, carefree days of the Red Wedding being the most shocking? How naïve we were.